Episode XV: Special Engines was uploaded on October 5, 2014, and is the fifth episode of the second season.
It's Toby's special day, and Bill and Ben try to guess what's so special about him with their not so great intellegence.
- Bill and Ben
- Sir Topham Hatt
- Mavis (does not speak)
- Boco (does not speak)
- James (cameo)
- Donald and Douglas (cameo)
- Henry (cameo)
- Oliver (cameo)
- Thomas (cameo)
- Diesel 10 (cameo)
- Annie and Clarabel (cameo)
- Sidney (mentioned)
- James Riddle: Toby
- DarthWill3: Bill, Ben and Diesel
- EnterprisingEngine93: Edward
- RightonTracks10: Percy
- Thomas1Edward2Henry3: Everyone else
- This is the first and only episode to feature DarthWill3 as Bill and Ben and also the return of RightonTracks10, but as Percy instead of Thomas. To add to that, it is the first episode since Stuck to feature James Riddle.
- The episode was originally planned for Mid-August release, but it was then pushed back to September so T1E2H3 could work on his own, non-Thomas films. Then, school started with more than expected amount of work, so the episode was further delayed.
- This marks the first proper appearance of Hilltrack's Trainz Routes's Bill and Ben models.
- The policemans "Oi! You!" from Thomas in Trouble/Thomas Breaks the Rules can be heard at the beginning as a joke.
- Henrietta is given a face for the first time. The face (which is really Rusty's) matches her face from the RWS rather the TV Series. It can also disappear and reappear.